I like to use straight-up eucalyptus eo for colds and stuffiness. I just dab some on a tissue and tuck it into my shirt pocket or bra.
but I'll bet if you melt some beeswax, add a little oil of choice, then scent with euc or other similar scents, you'd have a nice rub or salve. I would start with 1 part wax to 1/2 part oil, then adjust until you get the consistency you like.